Table 1.

Basic characteristics of study data for each visit type.

Characteristics		Derived cohorts		P value
		Readmitted (N = 5794)	Non-readmitted (N = 56,128)
Age, year, mean (SD)		75.2 (6.8)	74.7 (6.7)	0.000
Gender	Male, n (%)	54.8	49.7
	Female, n (%)	45.2	50.3
Age during hospital visit	60s	23.8	26.0
	70s	49.7	50.2
	80s	23.7	21.4
	90s	2.7	2.4
Season during admission	Spring	25.4	24.1	0.049
	Summer	25.5	26.8
	Fall	24.4	24.8
	Winter	24.6	24.3
Average length of stay, mean (SD)		2.5 (4.3)	0.2 (0.4)
Charlson comorbidity index, mean		1.11	0.52